Duplex engine.



W. WEEKS.

DUPLEX ENGINE.

APPLICATION FILED FEB. 15. I916.

1 ,271,966. Patented July 9, 1918.

2 SHEETS-SHEET INVENTOR WILLIAM VVEE ATTORNEY W. WEEKS.

DUPLEX ENGINE.

APPLICATION FILED FEB. 15, l9l6 2 SHEETS SHEET 2.

INVENTOR WILLIAM WEEKS ATTORNEY WILLIAM WEEKS, OF CHICAGO, ILLINOIS.

. DUPLEX ENGINE.

Specification of Letters Patent.

Patented July 9, 1918.

Application filed February 15, 1916. Serial No. 78,455.

To all whom it may concern:

Be it known that 1, WILLIAM WEEKS, a citizen of the Unit d States,residing at Chicago, in the couigy of Cook and State of Illinois, haveinven d certain new and useful Improvements in Duplex Engines, of whichthe following is a specification.

My invention relates to internal combustion engines of-the duplex typein which two alternately acting pistons are employed to propel the crankshaft of the engine.

An object of the invention is to reduce shocks in the engine bypermitting a slight compression in one of the'cylinders .at each upwardstroke.

A further object of my invention'is to so construct and arrange the mainor working cylinders of the engine with respect to an auxiliary cylinderas to provide communication therebetween.

I further contemplate a novel valve arrangement, and an operatingmechanism therefor, whereby the auxiliary piston may be caused tooperate on a two-cycle principle, and the working piston 0n thefourcycle principle, the several pistons cotiperating to continuouslydrive the crank shaft, a portion of the exhaust ases being utilized 7 tomove the auxiliary plston, and as a rein their preferred sult, obtain amaximum of power at the expenditure of a minimum quantity of fuel. Theabove and additional objects are accomplished by such means as areillustrated embodiment in the accompanying drawings, described in thefollowing specification and'then more particularly pointed out in theclaim which 1s a pended hereto and forms a part of this app ication.

In describing my invention in detail, reference will be had to theaccompanying drawings wherein like characters denote like orcorresponding parts throughout the several views, and in which Figure 1is a side elevation of my improved duplex engine, the crank case beingbroken away to illustrate the operating mechanism for the oscillatoryintermediate valves;

Fig. 2 is a detail longitudinal sectional view of said engine, and

Fig. 3 is a detail longitudinal sectional view of one of the saidoscillating intermediate valves.

Referring now to the drawings by numerals, 1 designates the crank case,2 the crank shaft, 3 the fly wheel, 4 the left hand working cylinder, 5the right hand working cylinder, 6 the intermediate or auxiliarycylinder, 7 the piston for the cylinder 4, 8 the piston for the cylinder5, 9 the piston for the cylinder 6, 10 the piston rod connecting thepiston. 7 and the crank shaft 2, 11 the piston rod connecting the piston8 and the crank shaft 2, 12 the piston rod connecting the piston 9 andthe crank shaft 2, 13 the spark plug for the cylinder, 4, 14 the sparkplug for the cylinder 5, '15 the intake valve mechanism for the cylinder4, 16 the intake valve mechanism for the cylinder 5, 17 the exhaustvalve mechanism for the cylinder 4, 18 the exhaust valve mechanism forthe cylinder 5, and-l9 an exhaust passage wa open to the respectivecylinders, that is, cy inders 4' and 5. Said cylinders. 4, 5 and 6 arejacketed as indicated at 20, the intermediate cylinder 16 being equippedwith an exhaust port 21, whereby, during reciprocation of the piston 9upon the two cycle principle, the burnt gases in said cylinder 6 may bepermitted to escape.

Intermediate oscillatory valves 22 and 23 are interposed respectivelybetween the cylindrs 4 and 6 and the cylinders 5 and 6, the

said valves, like the valves 15, 16, 17 and 18 (of the common type)being operatively associated and connected with a valve operating shaft24 mounted to extend parallel with the crank shaft 2. Each valve isequipped with a spring pressed valve operating rod 25 and with anassociate cam 26, the cams 26, being mounted on the shaft 24 toreciprocate the several valve rods and consequently open and close therespective valves at such times as may be required to a proper operationof the engine.

Upon reference to Fig. 3, it will be observed that the oscillatoryintermediate valves 22 and 23 are each jacketed as indicated at 27, saidvalves as hereinbefore stated, being located diametrically opposite withrespect to the cylinder 6 and at th top thereof to alternately open andclose communication between said cylinder 6 and the working cylinders 4and 5. By constructing the crank shaft 2 as illustrated in Fig. 2, it isevident that the stroke of the piston 9 is shorter than the stroke ofthe to acting pistons 7 and 8.

Pistons 7 and 8 alternately operate, that is, piston 8 is set to executeits power stroke while piston 7 its intake stroke, and vice versa. Eachof the several pistons, 7, 8 and 9 reciprocate in unison.

In operation, and assuming the parts to be in the position shown in Fig.2, and an explosion to be taking place in the top of cylinder 5, theforce of the explosion will be divided between pistons 8 and 9 inprovalv 23 is closed so that the gases thus confined in the top ofcylinder number 6 will be compressed, and the movement of the pistonwill thus be cushioned to prevent shocks to the engine.

At this moment an explosion will take place in the top of cylindernumber 4. and simultaneously therewith the valve 22 will .be opened sothat the' force of said explosion will be taken up jointly by pistons 7and 6 in proportion to their diameters whereby tomove the pistonsdownward and to permit piston 8 to draw in a fresh charge in the top ofcylinder number 5. Upon the return movement of the piston the processdescribed above will be repeated, at each upward movement of the pistona small quantity of exhaust gases being compressed in the top ofcylinder number 6 for the purpose described.

From the foregoing, taken in connection with the accompanying drawings,it will be noted that the intermediate auxiliary piston 9 is designed tooperate on the two cycle principle whil the working pistons? and 8 areoperated upon the four cycle principle; that all of the several pistonsmove in unison, the action on the piston 8, however, (during the intakestroke of the piston 7), causing the crank shaft 2 to be propelled.

In reduction to practice, I hav found that the form of my invention,illustrated in the drawings and referred to in the above de* scription,as the preferred embodiment is the most efficient and practical; yetrealizing that the conditions concurrent with the adoption of my devicewill necessarily vary, I desire to emphasize the fact that various minorchanges in details of construction, proportion and arrangement of partsmay be resorted to, when required, without sacrificing any of theadvantages of my invention, as defined in the appended claim.

Having thus fully described my invention, what I claim asnew and desireto secur by Letters Patent, is

In an internal combustion engine, the com; bination of a, pair of maincylinders, pistons operating therein, an intak valve for each cylinder,an exhaust manifold connecting said cylinders, an exhaust valve for eachcylinder controlling communication to said manifold, a crank shafthaving a major ofi'-' set portion, rods connecting said pistons to saidoffset, a minor offset portion in said major ofl'set portion, directedoppositely so as to produce a swing of less radius than th majorofl'set, an auxiliary cylinder having a normallyopen exhaust port, apiston operating therein, a rod connecting said piston with the minorofi'set, whereby all of the pistons are moved in unison in the samedirection, an oscillatory valve in each main cylinder controlling thecommunication between said cylinders and the auxiliary cylinder, anoperating means for said oscillatory valves whereby the main pistons mayoperate alternately on an explosion stroke and on the four cycleprinciple and the auxiliary cylinder receive a portion of the chargealternately from each main cylinder at each working stroke of saidauxiliary piston and exhaust the spent gases there-- from at each returnstroke of said auxiliary piston.

In testimony WhereofI aflix my signature in presence of two witnesses.

WILLIAM WEEKS.

Witnesses PATRICK W. CAREY, JOHN H. Hnnmucxsox.

